EFFECT OF LATERAL FRICTION IN THE VOLUMETRIC RESPONSE OF HIGHLY COMPACTED CLAY SAMPLES SUBMITTED TO OEDOMETRIC TEST

Abstract

The use of oedometer test to determine the volumetric response of soil samples dates from the beginnings of soil mechanics. Currently, the use of the test has been focused in the study of natural samples that are trimmed in thin wall rings, which do not generate initial stress states that could perturb the volumetric response of the sample. However, due to the increasing interest in studing highly compacted swelling soils, in the case of engineered barriers for nuclear waste disposal, this test has been conducted on samples directly compacted in the oedometer ring. This practice introduces an initial stress state that affects the volumetric response due to frictional effects. In this paper, some results of hydration tests on compacted swelling clay are presented to point out such effects, permitting to show the relevance of the way the samples are prepared, which is the goal of this work.